1. Field of the Invention
The present invention relates to a high-efficiency solid state power amplifier (SSPA). The SSPA has a mass of less than 850 g and includes two different X-band power amplifier sections, i.e., a lumped power amplifier with a single 11-W output and a distributed power amplifier with eight 2.75-W outputs. These two amplifier sections provide output power that is scalable from 11 to 15 watts without major design changes.
2. Description of the Related Art
The Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) NASA discovery mission is being designed to orbit and study the planet Mercury. After its scheduled launching in March 2004, the MESSENGER spacecraft will perform flybys of Venus and Mercury before going into orbit around the planet in April 2009.
The inner planet trajectory of the MESSENGER mission results in the need for a high-gain downlink to Earth in all directions around the spacecraft. In addition, the extreme thermal environment causes distortions to the antenna pattern of the traditional parabolic antennas. Phased-array antennas have had limited application in the deep-space community to date but one-dimensional electronically scanned antennas eliminate the use of deployed components and gimbal dish antennas and offer benefits of high-gain, low mass, and graceful degradation. Accordingly, two lightweight, phased-array antenna systems have been developed for use in the MESSENGER spacecraft for the high-gain downlink.
A need therefore exists for a high-efficiency power amplifier for use in powering a respective one of the two lightweight, phased-array antenna systems of the MESSENGER spacecraft.